Languages

• High-level Language

  A programming language that is easy for humans to understand
• Low-level Language

  A programming language that is close to what a CPU would actually do and is written for specific hardware
• High level must be compiled and interpreted into machine code before it can be run.
• High-level language: Advantages

  • One instruction high-level code represents many instructions of machine code
  • The same code will work for many different machines and processors
  • Code is easy to read, understand and modify
• High-level language: Disadvantages

  • Must be translated before a computer is able to understand it
  • You don't have much control over what the CPU actually does so programs will be less memory efficient and slower
• Low-level language: Advantages

  • Commands in machine code can be executed directly without the need for a translator
  • You control exactly what the CPU does and how it uses memory so programs will be more memory efficient and faster
• Low-level language: Disadvantages

  • One instruction of assembly code usually only represents one instruction of machine code
  • Usually written for one type of machine processor and won't work on any others
  • The programmer needs to know about the internal structure of the CPU and how it manages memory
  • Code is difficult to read, understand and modify
• Computers only understand instructions given to them as machine code, so high level languages need to be translated before the computer is able to execute the instructions.
• 2 Types of Translators:

  • Compiler
  • Interpreter
• Translators: Compiler

  • Translate all of the source code at the same time and creates one executable file
  • Only needed once to create the executable file
  • Returns a list of errors for the entire program once compiling is complete
  • Once compiled the program runs quickly but compiling can take a long time
• Translators: Interpreter

  • Translates and runs the source code one instruction at a time, but doesn't create an executable file
  • Needed every time you want to run the program
  • The interpreter will return the first error it finds and then stop- this is useful for debugging
  • Programs will run more slowly because the code is being translated as the program is running
• The type of translator will depend on which programming language and IDE you're using.
• Examples of high-level languages:

  • Python
  • Java
  • C++
• Examples of low-level languages:

  • machine code
  • assembly languages